Compositions and methods for reducing herbicidal injury

ABSTRACT

The disclosure herein relates to the use of organophosphorous compounds as antidotes for thiolcarbamate herbicides used in various crops, particularly grass crops, e.g., corn, rice, barley, sorghum and wheat.

This is a continuation-in-part of application Ser. No. 670,789 filed onMar. 26, 1976, now abandoned.

BACKGROUND OF THE INVENTION

The invention herein pertains to the field of crop protection.

This invention relates to novel compositions and methods for reducing ornullifying injury to young crop plants by selective herbicides. Morespecifically, this invention relates to novel compositions and methodsfor reducing injury to young grass crop plants, e.g., corn, rice,barley, sorghum and wheat by thiolcarbamate herbicides, such as diallateand triallate, which comprises treating the habitat of the crop plant orthe seed of the crop plant prior to planting, with an antidote for theselective herbicide.

Thiolcarbamate herbicides, such as diallate and triallate are veryuseful for controlling certain weeds in the presence of other growingplants. However, these herbicides sometimes injure certain crop plants,slowing growth and development at application rates necessary to stuntor kill the weeds. As a consequence, it is sometimes disadvantageous toemploy thiolcarbamate herbicides to control weeds in the presence ofcertain crops, some of which are important commodities in the world foodsupply. Obviously, there is a need for a method of reducing ornullifying the injury of the crop plant by the selective herbicide whilenot affecting the herbicidal action on the weeds to be controlled.

DESCRIPTION OF THE PRIOR ART

It is known in the prior art to reduce herbicidal injury to variouscrops by use of antidotal or "safening" compounds which have anantagonistic or nullifying effect with respect to the active ingredientsof the herbicide by one mechanism or another.

Illustrative of the use of antidotes for carbamate or thiolcarbamateherbicides in the prior art are U.S. Pat. No. 3,131,509 and SouthAfrican Patent Publication No. 72/2519. The '509 U.S. patent disclosesthe use of various hormone-type plant growth regulants, e.g., bromoalkylcompounds, as antagonists for certain carbamates. The South Africanpatent discloses the use of various acetamide and carbamate compounds asantagonists for thiolcarbamate herbicides. U.S. Pat. No. 4,036,628discloses the use of certain phosphate, phosphonate and phosphinatecompounds as antidotes for certain thiolcarbamate herbicides. However,the reference does not suggest that organothiophosphorous compoundswould have antidotal activity against thiolcarbamate herbicides.

There are, of course, many other compounds disclosed in the prior art asuseful antidotes for carbamate and acetanilide herbicides. However,organophosphorous compounds do not seem to have been widely used asantidotes for thiolcarbamate herbicides. In most of the art relevant touse of organophosphorous compounds in agriculture the use has been as aninsecticide, as a defoliant, as a herbicide, per se, or as a plantgrowth inhibitor of weeds or as fruit abscission agents. See, e.g., U.S.Pat. Nos. 3,879,189, 3,907,540, 3,861,899 and 3,826,640 as illustrativeprior art for the use of organophosphorous compounds in crop protectionuses.

SUMMARY OF THE INVENTION

The present invention relates to the use of certain organophosphorouscompounds as antidotal, antagonistic or safening agents for reducingcrop injury by thiolcarbamate herbicides. More particularly, thisinvention is primarily concerned with reducing injury to grass crops,e.g., barley, rice, sorghum and wheat, by the thiolcarbamate herbicidesdiallate or triallate.

Still more particularly, this invention relates to the use as antidotesfor thiolcarbamate herbicides of organophosphorous compounds defined bythe following formula ##STR1## wherein a, b and c represent the integerszero or one, but cannot all be zero simultaneously;

W, X and Z independently represent oxygen or sulfur;

R, R¹ and R² independently represent hydrogen, C₁₋₁₃ alkyl, lower alkylsubstituted lower alkyl, nitro lower alkyl, halo lower alkyl, loweralkenyl, halo lower alkenyl, lower alkynyl, halo lower alkylcarbonyl,halo lower alkenylsulfonyl lower alkyl, mono-lower alkyl amino, di-loweralkyl amino, halo lower alkenyl thio lower alkyl, lower mono- ordi-alkyl aminocarbonyl lower alkyl, lower mono- or di-alkylaminothiocarbonyl, halophenylthio, para-aminosulfonyl phenyl,para-nitrobenzoyl, halophenylthio lower alkyl, phenyl, benzyl, naphthyl,naphthyl substituted by one or two lower alkyl or halo moieties,α-nitromethylbenzyl, α-methylbenzyl, phenyl substituted by one to threeC₁₋₁₃ alkyl, lower alkenyl, halo, NO₂, CN, CF₃ and CH₃ S- moieties andno more than one of R, R¹ and R² can be quinolyl, 1-pyridinyl loweralkyl, 5-chlorothiophene-2-lower alkyl and N-lower alkyl di-lower alkylanilino carbonyl lower alkyl; provided that when a is 0, c is 1 and Z isS, R² cannot equal hydrogen or halophenyl; phenyl cannot be substitutedwith NO₂ and CF₃ simultaneously; when X and W are oxygen and Z is sulfurR, R¹ and R² cannot simultaneously equal CH₃ ; and W, X and Z are oxygenR, R¹ and R² cannot simultaneously equal phenyl.

In the above formula the term "alkyl" refers to a straight or branchedchain alkyl containing 1 to 13 carbon atoms. The preferred alkyls arethose containing 1-6 carbon atoms. The term "lower alkyl" is used hereinto refer to a straight or branched chain alkyl of from 1 to 6 carbonatoms, e.g., methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl and the like. Theterm "halo" or halogen includes chlorine, bromine, fluorine and iodineatoms. The term "lower alkenyl" is used herein to refer to an alkenylradical having from 2 to 6 carbon atoms, preferably from 3 to 5 carbonatoms. The term "lower alkynyl" is used herein to refer to an alkynylradical having 2 to 6 carbon atoms, preferably 3 to 4 carbon atoms. Theterm "carbonyl" when used herein is understood to mean ##STR2## radical;the term "thiocarbonyl" refers to the radical ##STR3##

As will be described in more detail below, certain subclasses oforganophosphorous compounds have exhibited a general pattern for degreesof effectiveness as antidotes for thiolcarbamate herbicides.

Other and interrelated aspects of this invention concern the provisionof safened compositions comprising thiolcarbamate herbicides, especiallydiallate and triallate, and an effective amount of an organophosphorousantidote, and to methods of reducing injury to young crop plants,particularly grass crops such as barley, rice, sorghum and wheat by useof said safened compositions. The preferred crop plant to be safened iswheat.

The preferred specific embodiment of the invention includes the safeningof, or reduction in injury to, wheat by triallate herbicide by use ofthe antidotal compound O,O-diethyl O-(m-tolyl) phosphorothioate.

The invention will be more clearly understood by reference to thefollowing detailed description of specific embodiments thereof.

DETAILED DESCRIPTION OF THE INVENTION

Compounds which are useful in reducing or eliminating crop injury arereferred to in the art variously as herbicidal antidotes, safeners orantagonistic agents. These compounds counteract the action of theherbicide to reduce injury to a given crop plant. In many instances weedinjury is also reduced, but to tolerable levels which are determined byeconomic factors.

In the practice of the present invention, organophosphorous compoundswithin the above generic formula are used as antidotal compounds withthiolcarbamate herbicides. For exemplary purposes herein thethiolcarbamates will be represented by triallate and diallate."Triallate" is the common name for the compoundS-(2,3,3-trichloroallyl)-diisopropylthiolcarbamate; "diallate" is thecommon name for the compoundS-(2,3-dichloroallyl)-diisopropylthiolcarbamate. Triallate and diallateare the active ingredients, respectively, in the herbicides Avadex BW®,FAR-GO® and Avadex®, (registered trademarks of Monsanto Company).

In studies of a large number and variety of organophosphorous compoundstested, analyses of test results with particular applicability totriallate, have shown the following general pattern of effectiveness asantidotes of various classes of organophosphorous compounds: ##STR4##

The compounds identified by structure in formulae I-V are known as: I,phosphorothioates, or thionophosphates; II, phosphonothioates; III,phosphinothioates; IV, phosphorodithioates and V, phosphonodithioates.

The amount of antidote employed in methods and compositions of thisinvention will vary according to the particular herbicide with which theagent is employed and the rate of application of the herbicide. In eachinstance the amount of antidote employed is an effective safeningamount. By an effective safening amount is meant an amount which reducescrop injury by the herbicide. In the tests employed in illustrating thisinvention, the amount of crop injury was reduced by as much as 100percent.

The compounds used herein as antidotes for thiolcarbamate herbicides areeither known compounds or are readily prepared from known compounds byknown and/or conventional methods of preparation.

The method and compositions of this invention are exemplified by theexamples below.

EXAMPLES 1 THROUGH 75

The safening effectiveness of representative antidotes on triallateherbicide with respect to wheat is shown by the test results presentedin Table I. For each antidote there is shown the antidote safeningeffect of the antidote in terms of reduction in percent crop injury. The"percent safening effect" is determined by the following calculation: [%inhibition of plant caused by herbicide alone+% inhibition of plantcaused by antidote]-% inhibition of plant caused by herbicide/antidotecombination. These results are obtained by the following procedure.

A good grade of top soil is placed in an aluminum pan and compacted to adepth of 9.5 to 12.7 mm. from the top of the pan. A predetermined numberof seeds of each of the plant species to be tested are placed on top ofthe soil in the pans. A quantity of soil sufficient to substantiallyfill the pan is measured and placed in a suitable container. A measuredquantity of the antidote compound dispersed or dissolved in a suitablecarrier is sprayed on the soil in the container. A measured quantity ofthe triallate herbicide dispersed or dissolved in a suitable carrier isthen sprayed on the soil in the container already treated with thesafening agent. The quantity of triallate herbicide and antidote used isexpressed in terms of kilograms per hectare. The soil containing theantidote and triallate herbicide is thoroughly mixed. The mixing issometimes referred to as incorporation of the herbicide and antidoteinto the soil. The mixing or incorporation provides a substantiallyuniform distribution of the antidote and herbicide throughout the soil.The seeds are covered with the soil containing the antagonistic agentand triallate herbicide and the pans are leveled. The pans are thenplaced on a sand bench in the greenhouse and watered from below asneeded. The plants are observed at the end of approximately 21 days andthe results in terms of percent inhibition of each crop species arerecorded. For each test series a pan of plants is also preparedcontaining no herbicide and no antidote as a control. Additionally, foreach test, a pan of plants is prepared with soil covering the seedcontaining no triallate herbicide and only the measured amount ofantidote being incorporated into the soil covering the seeds toascertain any herbicidal effect of the antidote alone. For each seriesof tests the herbicidal effect of the triallate is observed from pans ofplants treated with the same quantity of herbicide alone.

                                      TABLE 1                                     __________________________________________________________________________         Amount of                         Amount of                                                                           Percent                          Example                                                                            Triallate                         Antidote                                                                            Safening                         No.  (Kg/Ha)                                                                               Antidote Compound         (Kg/Ha)                                                                             Effect                           __________________________________________________________________________    1    0.14  0,0-Diethyl S--(methyl-2,6-xylylcarbamoylmethyl)                                                          8.96  55                                          phosphorodithioate                                                 2    0.28  0-(2-Chloro-4-nitrophenyl) 0,0-diethyl phosphoro-                                                         4.48  20                                          thioate                                                            3    0.28  0-(3-Cyanophenyl) 0,0-diethyl phosphorothioate                                                            8.96  70                               4    0.28  S--(3,3-Dichloroallyl) 0,0-dimethyl phosphoro-                                                            8.96  40                                          dithioate                                                          5    0.28  0-(3,3-Dichloroallyl) 0,0-diethyl phosphoro-                                                              4.48  35                                          thioate                                                            6    0.28  S--(3,3-Dichloroallyl) 0,0-diethyl phosphoro-                                                             8.96  50                                          dithioate                                                          7    0.28  0,0-Diethyl S--(1-methyl-2-nitroethyl) phosphoro-                                                         8.96  30                                          dithioate                                                          8    0.28  S--(2,3-Dibromoallyl) 0,0-diethyl phosphorodi-                                                            4.48  30                                          thioate                                                            9    0.28  0,0-Diethyl 0-(4-sulfamylphenyl) phosphorothioate                                                         8.96  80                               10   0.28  S--(3,3-Dichloroallylthiomethyl)0,0-diethyl phos-                                                         8.96  60                                          phorodithioate                                                     11   0.28  0,0-Diethyl-0-p-nitrophenyl phosphorothioate                                                              8.96  50                               12   0.28  0,0-Dimethyl-0-p-nitrophenyl phosphorothioate                                                             8.96  60                               13   0.28  S--{[(p-chlorophenyl)thio]methyl}0,0-diethyl                                                              8.96- 45                                          phorodithioate                                                     14   0.28  0,0-Dimethyl 0-[4-(methylthio)-m-tolyl] phosphoro-                                                        4.48  85                                          thioate                                                            15   0.28  0,0-Dimethyl 0-(4-nitro-m-tolyl) phosphorothioate                                                         4.48  20                               16   0.28  0,0-Dimethyl 0-(2,4-5-trichlorophenyl) phosphoro-                                                         4.48  35                                          thioate                                                            17   0.28  S[(3-chloro-2-butenyl sulfonyl)methyl] 0,0-diethyl                                                        8.96  30                                          phosphorodithioate                                                 18   0.56  S--(2-bromoallyl) 0,0-diethylphosphorodithioate                                                           8.96  80                               19   0.56  S--(α-methyl benzyl) 0,0-diethyl phosphorodithioate                                                 8.96  90                               20   0.56  0,0-Diethyl 0(p-trifluoromethylphenyl) phosphoro-                                                         8.96  95                                          thioate                                                            21   0.28  0,0-Diethyl S--(1-naphthylmethyl) phosphorodithioate                                                      8.96  20                               22   0.28  0,0-Diethyl S--2-propynyl phosphorodithioate                                                              8.96  45                               23   0.28  0,0,0-tributyl phosphorothioate                                                                           8.96  55                               24   0.28  S--Chloroacetyl) 0,0-diisopropylphosphorodithioate                                                        8.96  20                               25   0.28  S,S--(p-chlorophenyl)0,0-diisopropyl peroxy-phos-                                                         4.48  30                                          phorotrithioate                                                    26   0.28  0,0-Diisopropyl S,S--(O--nitrophenyl) peroxyphos-                                                         8.96  25                                          phorotrithioate                                                    27   0.28  Diethyldithiolcarbamic acid-0,0-diisopropyl S--hydrogen                                                   4.48  50                                          phosphorodithioate mixed anhydrosulfide                            28   0.28  0,0-Diisopropyl S--[2-(2-pyridyl)ethyl] phosphoro-                                                        8.96  55                                          dithioate                                                          29   0.28  S--[1-(ethoxycarbonyl)ethyl]0,0-diisopropyl phos-                                                         8.96  40                                          phorodithioate                                                     30   0.42  S--(5-chloro-2-thienyl) 0,0-diisopropylphosphoro-                                                         8.96  43                                          dithioate                                                          31   0.42  0,0-Dipropyl S--hydrogen phosphorodithioate                                                               4.48  23                               32   0.42  S--(3,3-Dichloroallyl)0,0-diisopropyl phosphorodi-                                                        4.48  97                                          thioate                                                            33   0.42  S--(3,3-Dichloroallyl)0,0-dipropyl phosphorodithioate                                                     8.96  92                               34   0.42  0,0-Dibutyl S--(3,3-dichloroallyl) phosphorodithioate                                                     8.96  22                               35   0.42  0,0-Dibutyl S--[α-(nitromethyl)benzyl] phosphoro-                                                   8.96  32                                          dithioate                                                          36   0.42  0,0-Bis(2,4-dichlorophenyl) S--[α-(nitromethyl)benzyl]                                              8.96  18                                          phosphorodithioate                                                 37   0.42  0,0-Ditridecyl S--hydrogen phosphorodithioate                                                             8.96nched                                                                           23                                          C.sub.13)                                                          38   0.42  0,0-Bis(p-dodecylphenyl) S--hydrogen phosphoro-                                                           8.96  18                                          dithioate (branched C.sub.12)                                      39   0.42  0,0-Bis(2,4-dichlorophenyl) S--hydrogen phosphoro-                                                        8.96  23                                          dithioate-p-nitrothiolbenzoic acid mixed anhydro                              sulfide                                                            40   0.42  S--[α-(nitromethyl)benzyl]0,0-diphenylphosphorodi-                                                  8.96  18                                          thioate                                                            41   0.28  O--Methyl S--hydrogen phenyl phosphonodithioate                                                           4.48  35                               42   0.28  O--Phenyl N--isopropyl p-methyl phosphonoamidothioate                                                     4.48  40                               43   0.28  0-(p-Chlorophenyl) N--isopropyl-p-methylphosphono-                                                        4.48  20                                          amidothioate                                                       44   0.28  S--benzyl O--ethyl methylphosphonodithioate                                                               8.96  65                               45   0.28  0-(m-isopropylphenyl)-N--methyl methyl phosphono-                                                         4.48  45                                          amidothioate                                                       46   0.28  0,0-diethyl-0-m-tolyl phosphorothioate                                                                    8.96  80                               47   0.28  0-(3,3-Dichloroallyl) O--ethyl methylphosphonothioate                                                     8.96  50                               48   0.28  O--Ethyl 0-(2,3,3-trichloroallyl) methylphosphono-                                                        8.96  35                                          thioate                                                            49   0.28  0-(2,3,3-Trichloroallyl) S--hydrogen methylphos-                                                          1.12  50                                          phonodithioate                                                     50   0.28  O--Butyl 0-(3-trifluoromethylphenyl) methylphos-                                                          8.96  80                                          phonothioate                                                       51   0.28  0-(4-Cyano-3-trifluoromethylphenyl)0-n-propyl                                                             8.96  30                                          methylphosphonothioate                                             52   0.28  S--(N--methylcarbamoylmethyl)0--methyl phenylphos-                                                        8.96  25                                          phonodithioate                                                     53   0.28  S,S--diallyl methylphosphonotrithioate                                                                    4.48  30                               54   0.28  0-(2,6-Dibromophenyl)O--ethyl methylphosphonothioate                                                      8.96  45                               55   0.28  0-(2-Chloroethyl)0-(4-cyanophenyl) isopropylphos-                                                         8.96  45                                          phonothioate                                                       56   0.56  0-(4-Chloro-m-tolyl)O--ethyl methylphosphonothioate                                                       4.48  45                               57   0.56  0-(o-Chlorophenyl)O--ethyl methylphosphonothioate                                                         8.96  95                               58   0.56  O--Ethyl N,N--diethyl P methylphosphonoamidothioate                                                       8.96  30                               59   0.28  O--Ethyl S--2-propynyl methylphosphonodithioate                                                           8.96  20                               60   0.28  S--(P--chlorophenylthiomethyl)O--isopropylmethylphos-                                                     8.96  55                                          phonodithioate                                                     61   0.28  0-(2-Allyl-6-chloro-phenyl)O--ethyl methylphosphono-                                                      8.96  70                                          thioate                                                            62   0.28  0-(4,6-Dichloro-m-tolyl)O--ethyl methylphosphono-                                                         8.96  45                                          thioate                                                            63   0.14  O--Ethyl 0-(p-tolyl) methylphosphonothioate                                                               8.96  43                                    0.28  O--Ethyl 0-(p-tolyl) methylphosphonothioate                                                               8.96  80                               64   0.28  Methylphenylphosphinodithioic acid                                                                        4.48  35                               65   0.28  O--Phenyl dimethylphosphinothioate                                                                        8.96  40                                    0.14  O--Phenyl dimethylphosphinothioate                                                                        8.96  55                               66   1.12  0-(2,6-Xylyl) dimethylphosphinothioate                                                                    8.96  23                                    0.56  0-(2,6-Xylyl) dimethylphosphinothioate                                                                    8.96  65                                    0.28  0-(2,6-Xylyl) dimethylphosphinothioate                                                                    8.96  70                                    0.14  0-(2,6-Xylyl) dimethylphosphinothioate                                                                    8.96  50                               67   0.28  S--(2,4-Xylyl)dimethylphosphinodithioate                                                                  8.96  30                               68   0.28  0-(2-Isopropyl-6-methyl-4-pyrimidynyl) dimethyl-                                                          8.96  15                                          phosphinothioate                                                   69   0.28  0-(2,3,3-Trichloroallyl) dimethyl phosphinothioate                                                        8.96  30                               70   0.28  0-(2,4-Dichloro-1-naphthyl) dimethyl phosphinothioate                                                     8.96  40                               71   0.28  S--(2-Chloroallyl)0,0-diethyl phosphorothioate                                                            8.96  50                               72   0.28  S--(4-chlorophenyl S--phenyl methyl phosphonotrithioate                                                   8.96  15                               73   0.56  S--Hydrogen 0,0-diethyl phosphorodithioate                                                                8.96  25                               74   0.28  0,0,0-triethyl phosphorothioate                                                                           8.96  25                               75   0.28  0,0-dibutyl 0-(p-nitrophenyl) phosphorothioate                                                            8.96  15                               __________________________________________________________________________

Further exemplification of the use of representative organophosphorouscompounds as antidotes for thiolcarbamate herbicides is presented inTables 2 and 3. In the tables the antidotal effect of variousorganophosphorous compounds is shown with triallate in the grass cropsbarley, rice, sorghum and/or wheat. In these tests theherbicide/antidote was applied by incorporation in the soil. In Table 2the expression "Δ Inhibition (%)" above the plants refers to the changein percent inhibition of plant growth resulting from treating the plantswith a safened composition comprising the herbicide and the antidotevis-a-vis the percent inhibition of plant growth caused by the herbicidealone. The amount of said change in percent inhibition is expressed inplus (+) and minus (-) values representing, respectively, an increase ordecrease in the percent inhibition resulting from the presence of theantidote.

                                      TABLE 2                                     __________________________________________________________________________                                  ΔInhibition (%)                                                     Rate                                                                              Plant                                           Herbicide                                                                           Kg/Ha                                                                             Antidote        Kg/Ha                                                                             Barley                                                                             Rice                                                                             Sorghum                                                                            Wheat                              __________________________________________________________________________    Triallate                                                                           0.28                                                                              0,0-diethyl O--phenyl phos-                                                                   4.48                                                                              0    +15                                                                              -55  -55                                          phorothioate                                                        Triallate                                                                           0.28                                                                              O--(2,6-xylyl) dimethyl-                                                                      8.96                                                                              0    +10                                                                              -55  -65                                          phosphinothioate                                                    Triallate                                                                           0.28                                                                              O--m-tolyl dimethylphos-                                                                      8.96                                                                              0    -55                                                                              -40  -10                                          phinothioate                                                        Triallate                                                                           0.28                                                                              O--methyl S--hydrogen phenyl                                                                  4.48                                                                              +10  +25                                                                              -15  -35                                          phosphonodithioate                                                  Triallate                                                                           0.28                                                                              S--benzyl O--ethyl methyl-                                                                    8.96                                                                              +10  -55                                                                              -65  -65                                          phosphonodithioate                                                  __________________________________________________________________________

Some effects resulting from variations in concentration of triallateherbicide at constant antidote concentration are shown in Table 3 forrepresentative organophosphorous antidotes. The herbicide/antidotecomposition was applied by incorporation in the soil. An interestingobservation to be noted in the date from these tests is that with mostof the antidotes the herbicidal action of triallate in barley isdecreased with increasing concentration of triallate, whereas theopposite effect is noted with certain exceptions, in sorghum and wheat.

                                      TABLE 3                                     __________________________________________________________________________                                   ΔInhibition (%)                                               Rate Triallate                                                                          PLANT                                          Antidote             (Kg/Ha)                                                                            (Kg/Ha)                                                                            Barley                                                                            Sorghum                                                                            Wheat                                 __________________________________________________________________________    O--Phenyl dimethyl phosphinothioate                                                                8.96 1.12 0   0    0                                                               0.56 +5  -3   0                                                               0.28 +10 -8   -40                                                             0.14 +10 -65  -55                                   0-(2,6-xylyl) dimethylphosphinothioate                                                             8.96 1.12 +15 -38  -23                                                             0.56 -5  -63  -65                                                             0.28 -10 -68  -70                                                             0.14 +10 -65  -50                                   O--Methyl S--hydrogen phenyl phosphono-                                                            4.48 1.12 -10 0    0                                     dithioate                 0.56 0   0    0                                                               0.28 0   0    -50                                                             0.14 +25 -65  -45                                   O--Phenyl N--isopropyl P--methyl phos-                                                             4.48 1.12 -30 -53  -3                                    phonoamidothioate         0.56 +15 -88  -50                                                             0.28 +10 -88  -60                                                             0.14 +20 -90  -65                                   S--benzyl O--ethyl methylphosphonodi-                                                              8.96 1.12 -25 -63                                        thioate                   0.56 +10 -73  -85                                                             0.28 +20 -73  -90                                                             0.14 +10 -70  -65                                   0,0-Diethyl S--(methyl-2,6-xylyl carba-                                                            8.96 1.12 -40 0    0                                     moylmethyl) phosphorodithioate                                                                          0.56 -5  0    -5                                                              0.28 0   -8   -20                                                             0.14 +10 -70  -55                                   __________________________________________________________________________

In a preferred embodiment of this invention the antidote compound isapplied to the crop seed to reduce, minimize or eliminate crop injury bythe herbicide.

In order to counteract injury by the herbicide, the crop seed need betreated with only a small amount of the antidote. For example,application rates of about 1100 g. to as low as about 1.5 g of antidoteper bushel of seed may be used. The presently preferred application rateis in the range of about 1.5 g. to 550 g. of agent per bushel. The seedis treated with the antidote compound by use of conventional seedtreating apparatus well known to the art. The seed is thoroughly mixedwith the antidote in the seed treating apparatus, thereby giving a seedwhich is coated with the agent.

Since only a very small amount of antidote is required for the seedtreatment, the compound may be formulated as a wettable powder or anemulsifiable concentrate which can be diluted with water by the seedtreater for use in the seed treating apparatus. Alternatively, theantidote may be dissolved or suspended in an organic solvent for use asa seed treatment or the pure compound alone may be used under properlycontrolled conditions.

There are thus provided by this invention novel seed treatingcompositions containing one or more of the described active antidotesintimately dispersed in an inert carrier or diluent for the intendeduse. Such carriers may be either solid such as talc, clay, diatomaceousearth, sawdust, calcium carbonate, and the like or liquids such aswater, kerosene, acetone, benzene, toluene, xylene, chlorinatedhydrocarbons and the like in which the antidote may be either dissolvedor dispersed. Emulsifying agents are advisably used to achieve asuitable emulsion if two immiscible liquids are used as a carrier.Wetting agents may also be used to aid in dispersing the activeantagonistic agent in liquids used as a carrier in which the agent isnot completely soluble. Emulsifying agents and wetting agents, alsoknown as "surface active agents", are sold under numerous tradenames andmay be either pure compounds, mixtures of compounds of the same generalgroups, or they may be mixtures of compounds of different classes.Typical satisfactory surface active agents which may be used are alkalimetal higher alkylarylsulfonates such as sodium dodecylbenzenesulfonateand the sodium salts of alkylnaphthalenesulfonic acids, fatty alcoholsulfates such as the sodium salts of monoesters of sulfuric acid withn-aliphatic alcohols containing 8-18 carbon atoms, long chain quaternaryammonium compounds, sodium salts of petroleum-derived alkylsulfonicacids, polyethylene sorbitan monooleate, alkylaryl polyether alcohols,water-soluble lignin sulfonate salts, alkali-casein compositions, longchain alcohols usually containing 10 to 18 carbon atoms, andcondensation products of ethylene oxide with fatty acids, alkylphenolsand mercaptans.

EXAMPLE 75

This example illustrates the safening effect of variousorganophosphorous compounds on thiolcarbamate herbicides in wheat whenthe antidote is applied as a seed treatment at varying concentrations.

The procedure used for the tests in this example was as follows:

Toluene solutions or suspensions of the antidote compounds were appliedto wheat seeds to obtain the desired concentrations. Untreated weeds,e.g., wild oats (WO), downy brome grass (DB), blackgrass (BG) and greenfoxtail (FT), along with the treated and untreated wheat seeds, wereplanted in containers containing Ray silt loam soil. Soil cover layerswere placed on the pre-seeded containers. In tests using thethiolcarbamate herbicide, e.g., triallate, the herbicide was applied tothe soil cover layer with a belt sprayer and incorporated into the soil.The treated soil layers were then placed on the pre-seeded containers.The containers were then transferred to greenhouse benches andsubirrigated through sand as needed. The results were observed aboutthree weeks after initiation of the tests and tabulated in Table 4. Inthe table, a dash (-) indicates that the named weed species was nottested.

                                      TABLE 4                                     __________________________________________________________________________                       % Wheat Inhibition                                         Amount of   Antidote                                                                             Treatment Conc. gm of                                                                     % Inhibition                                   Herbicide   Compound of                                                                          Antidote/Kg of Seed                                                                       Grass Weeds                                    Herbicide                                                                           Kg/Ha Example No.                                                                          0  .031                                                                             .125                                                                             .5 DB FT BG WO                                    __________________________________________________________________________    Triallate                                                                           0     46     0  10 10 15 0  -- 0  0                                           0.035        0  0  0  15 60 -- 20 90                                          0.07         10 0  10 15 100                                                                              -- 80 95                                          0.14         45 0  0  10 100                                                                              -- 90 100                                         0.28         65 0  0  10 100                                                                              -- 98 95                                          0.56         98 70 0  10 100                                                                              -- 98 100                                         1.12         98 80 15 15 100                                                                              -- 100                                                                              100                                         2.24         98 98 60 25 100                                                                              -- 100                                                                              100                                   Triallate                                                                           0      3     0  0  10 15 0  -- 0  0                                           0.035        0  0  10 40 40 -- 25 45                                          0.07         40 0  0  30 100                                                                              -- 45 98                                          0.14         50 0  0  15 100                                                                              -- 70 98                                          0.28         80 0  0  15 100                                                                              -- 98 100                                         0.56         95 10 10 15 100                                                                              -- 100                                                                              100                                         1.12         98 30 15 40 100                                                                              -- 100                                                                              100                                         2.24         100                                                                              25 0  35 100                                                                              -- 100                                                                              100                                   Triallate                                                                           0     10     0  0  20 0  0  -- 0  0                                           0.035        0  0  10 20 20 -- 10 90                                          0.07         0  0  0  20 80 -- 75 98                                          0.14         20 0  10 15 98 -- 80 95                                          0.28         80 10 10 30 100                                                                              -- 98 95                                          0.56         80 25 25 30 100                                                                              -- 98 100                                         1.12         95 80 70 40 100                                                                              -- 100                                                                              100                                         2.24         100                                                                              90 85 70 100                                                                              -- 100                                                                              100                                   Triallate                                                                           0     48     0  0  0  15 0  -- 0  0                                           0.035        0  0  0  25 40 -- 40 75                                          0.07         25 0  0  45 80 -- 80 98                                          0.14         45 15 0  25 95 -- 90 100                                         0.28         60 30 0  25 98 -- 98 95                                          0.56         90 30 25 45 100                                                                              -- 100                                                                              100                                         1.12         98 90 60 35 100                                                                              -- 98 100                                         2.24         100                                                                              90 90 40 100                                                                              -- 100                                                                              100                                   Triallate                                                                           0     50     0  10 10 30 0  -- 0  0                                           0.035        0  0  0  60 20 -- 30 50                                          0.07         10 0  0  45 75 -- 75 98                                          0.14         30 10 0  10 98 -- 70 95                                          0.28         75 10 20 10 100                                                                              -- 98 98                                          0.56         95 50 20 30 100                                                                              -- 98 90                                          1.12         98 80 75 45 100                                                                              -- 100                                                                              98                                          2.24         100                                                                              90 80 65 100                                                                              -- 100                                                                              100                                   Triallate                                                                           0     54     0  0  0  10 0  0  -- 0                                           0.035        0  0  0  15 60 0  -- 85                                          0.07         0  0  0  15 80 30 -- 95                                          0.14         35 0  0  15 95 20 -- 100                                         0.28         60 0  0  20 100                                                                              40 -- 100                                         0.56         90 45 10 30 100                                                                              60 -- 100                                         1.12         98 75 25 20 100                                                                              80 -- 100                                         2.24         100                                                                              80 70 55 100                                                                              85 -- 100                                   Triallate                                                                           0     56     0  0  5  45 0  0  -- 0                                           0.35         0  15 35 60 60 0  -- 65                                          0.07         0  0  5  20 80 0  -- 90                                          0.14         15 0  30 60 98 15 -- 100                                         0.28         60 15 25 50 100                                                                              25 -- 100                                         0.56         85 20 15 55 100                                                                              35 -- 100                                         1.12         98 60 25 40 100                                                                              50 -- 100                                         2.24         100                                                                              80 50 55 100                                                                              70 -- 100                                   Triallate                                                                           0     57     0  0  0  55 0  0  -- 0                                           0.035        0  0  0  50 80 0  -- 95                                          0.07         0  0  0  65 95 0  -- 100                                         0.14         0  15 0  65 100                                                                              10 -- 100                                         0.28         60 0  0  60 100                                                                              25 -- 100                                         0.56         70 20 15 70 100                                                                              35 -- 100                                         1.12         90 30 30 75 100                                                                              45 -- 100                                         2.24         95 55 40 60 100                                                                              70 -- 100                                   Triallate                                                                           0     63     0  0  25 30 0  0  -- 0                                           0.035        0  0  25 30 70 0  -- 75                                          0.07         0  0  25 55 90 0  -- 95                                          0.14         20 0  20 60 98 20 -- 100                                         0.28         65 10 15 35 100                                                                              35 -- 100                                         0.56         80 35 15 90 100                                                                              40 -- 100                                         1.12         95 50 10 30 100                                                                              55 -- 100                                         2.24         100                                                                              75 40 55 100                                                                              70 -- 100                                   __________________________________________________________________________

In addition to applying the herbicide/antidote safening composition byincorporating the components into the soil or by seed treatment with theantidote, it will be understood by those skilled in the art that anyconventional alternative modes of application may be used. For example,the herbicide and antidote may be applied simultaneously, e.g., as atank mix, or sequentially to the surface of the soil in which the seedsare planted prior to emergence of the plants or the herbicide andantidote may be applied postemergently after the plants have emerged.These alternative modes of application of herbicide and/or antidote areconventional practices in the crop protection art.

As indicated above in the section entitled "Detailed Description of theInvention", the organophosphorous compounds used as antidotes herein areall known and/or readily prepared by conventional processes as will beapparent to those skilled in the art. For example, typical methods ofpreparation, including alternatives, for preparing phosphates,phosphites, phosphorothioates (thionophosphates) or -dithioates,phosphonates, phosphonothioates and -dithioates, phosphinates and theirsulfur analogs, and miscellaneous phosphorous compounds such as theamides, amines, etc., of phosphorous and phosphoric acids, e.g.,phosphoroamidates, etc., are described in "Organo-phosphorous Compounds"by G. M. Kosolapoff, published by John Wiley and Sons, Inc., New York(1950) and in "Encyclopedia of Chemical Technology" (Edited by R. E.Kirk and D. F. Othmer), Vol. 10, pates 494-505 (1953); published by TheInterscience Encyclopedia, Inc., New York.

While this invention has been described with respect to certainembodiments, it is to be understood that it is not so limited and thatvariations and modifications thereof obvious to those skilled in the artto which this invention appertains can be made without departing fromthe spirit or scope thereof.

We claim:
 1. A method of reducing injury to grass crops by diallate andtriallate herbicides which comprises applying to the soil, crop or cropseed an effective safening amount of a compound of the formula ##STR5##wherein R and R¹ independently represent hydrogen, C₁₋₁₃ alkyl, nitrolower alkyl, halo lower alkyl; R² is equal to phenyl, phenyl substitutedby one to three C₁₋₁₃ alkyl, lower alkyl, halo, NO₂, CN, CF₃ and CH₃S-moieties or para-amino sulfonylphenyl; provided that phenyl cannot besubstituted with NO₂ and CF₃ simultaneously.
 2. A method of claim 1wherein said herbicide is triallate.
 3. A method of claim 1 wherein saidcrops are corn, barley, rice, sorghum and wheat.
 4. A method of claim 3wherein said crop is wheat and sorghum.
 5. A method of claim 4 whereinsaid crop is wheat.
 6. A method of reducing injury to grass crops bydiallate and triallate herbicides which comprises applying to the soil,crop or crop seed an effective safening amount of a compound selectedfrom the group consisting of O,O-Diethyl O-(4-sulfamylphenyl)phosphorothioate, O,O-Dimethyl O-(4-(methylthio)-m-tolyl)phosphorothioate, O,O-Diethyl O-(p-Trifluoromethylphenyl)phosphorothioate, O,O-Diethyl O-(m-tolyl) phophorothioate.
 7. A methodof claim 6 wherein the compound is O,O-Diethyl O-(m-tolyl)phosphorothioate.
 8. A method of claim 7 wherein said compound isapplied to the seed.
 9. A method of claim 1 wherein said compound isapplied to the soil.
 10. A method of claim 1 wherein said compound isapplied to the soil and incorporated into the soil.
 11. A method ofclaim 1 wherein said compound is applied to the seed.
 12. A safenedherbicide composition comprising diallate or triallate herbicide and aneffective safening amount of a compound selected from the groupconsisting of O,O-Diethyl O-(4-sulfamylphenyl) phosphorothioate,O,O-Dimethyl O-(4-methylthio)-m-tolyl) phosphorothioate, O,O-DiethylO-(p-Trifluoromethylphenyl) phosphorothioate, O,O-Diethyl O-(m-tolyl)phosphorothioate.
 13. A composition of claim 12 wherein the compound isO,O-Diethyl O-(m-tolyl) phosphorothioate.
 14. A safened herbicidecomposition comprising diallate or triallate herbicide and an effectivesafening amount of a compound of the formula of ##STR6## wherein R andR¹ independently represent hydrogen, C₁₋₁₃ alkyl, nitro lower alkyl,halo lower alkyl; R² is equal to phenyl, phenyl substituted by one tothree C₁₋₁₃ alkyl, lower alkenyl, halo, NO₂, CN, CH₃ S-moieties orpara-amino sulfonylphenyl; provided that phenyl cannot be substitutedwith NO₂ and CF₃ simultaneously.
 15. A composition according to claim 14wherein said herbicide is triallate.